Class with composite Key, attribute and relation

Question

Hello
I am implementing the jpa part of my project however I have a quite common relation to set up between 2 tables and I think I am in the wrong way
I have 3 entities : question - answer and project
The code below should allow you to understand easierly :
----- project
public class Project implements Serializable{
     private static final long serialVersionUID = 6478117913922953539L;
     @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
     private Long ProjId;
     @Column(nullable = false)
     private String Name;
     @OneToMany(mappedBy="project",targetEntity=AnswerPK.class)
     private List<Answer> Answers;
------- question
public class Question implements Serializable{
     private static final long serialVersionUID = -1231353969246302525L;
     @Id @GeneratedValue
     private Long QuestId;
     @Column(nullable = false)
     private String Label;
     @Column(nullable = false)
     private String Type;
-------- Answer
public class Answer implements Serializable{
     private static final long serialVersionUID = -690621748466361598L;
     @EmbeddedId
     private AnswerPK key;
     private String result;
----------- AnswerPK
public class AnswerPK implements Serializable { 
     private static final long serialVersionUID = 9172011321649468776L;
     @ManyToOne(optional=false)
     @JoinColumn(name = "ProjId",nullable = false)
     private Project project;
     @OneToOne(optional=false)
     @JoinColumn(name = "QuestId",nullable = false)
     private Question question;
however I got this error
Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.unmod.Domain.Project.Answers[com.unmod.Domain.AnswerPK]
so I start thinking that's not the way to do that

Answer 1

Numerous other things started going odd so I cleared out and re-installed jdev.
The entities are generated correctly now.
blew 4 hours on it though